SCOTTSDALE, Ariz. — Jon Gray is jazzed. Not about his six-inning, 88-pitch effort in a minor-league scrimmage on a back field here Wednesday. His line was nothing special: four runs (three earned), on five hits with seven strikeouts and no walks. Catching prospect Dom Nunez tagged him for a two-run home run. Rather, what had Gray bubbling with optimism afterward was his overall performance this spring, which has him primed for Monday’s season opener at Milwaukee.